Geographic Range

Coccinella septempunctata originated in Europe and Asia, but is now found throughout the Middle East, India and North America (U.S. and Canada). Several intentional introductions of C. septempunctata occurred between 1951 to 1971 in the U.S. for biological control of crop threatening aphids. None of these releases were thought to be successful in creating a natural population until 1973 when an established population was found in Hackensack Meadowland, New Jersey. However, this population was thought to have arisen from an accidental release. Populations continued to arise in the eastern U.S. and Canada, either purposefully or unintentionally in the following years. Since then, this species has become one of the most common and widespread coccinellid species in the Nearctic range. (Gordon, 1985; Honek and Martinkova, 2005; Maredia, et al., 1992)

Physical Description

Coccinella septempunctata looks like the quintessential ladybug: it is medium sized, has orangish-red elytra and black spots. It can be identified however, by several distinct characteristics. This species typically has seven black spots on its elytra (although it can range from 0 to 9). There is one spot next to the scutellum that bridges the junction between the two elytra; there are two white patches on either side of the scutellum, just above this black scutellar spot. The three spots on each elytra are variable in placement, but are generally rather bold. This species also has two characteristic pale white spots along the anterior side of the pronotum. The ventral side of the abdomen is convex and is almost exclusively black; males have slight hairs on the last abdominal segment. (Angalet, et al., 1979; Cantrell, 2011; Gordon, 1985)

The pupa is slate grey to black, sometimes having white or orange markings on the outside. It has a hardened exoskeleton which develops from the fourth instar. Its size is approximately the size of the adult Coccinella septempunctata. ("Coccinella septempunctata L.", 2011; Cantrell, 2011)

Development

After emergence from the egg, a larva will remain with its egg casing, eat it, and eat any infertile eggs in the vicinity. As the instars develop, they shift from sucking aphid liquids as meals to eating the entire insect. Coccinella septempunctata has four instars, the lengths of which are largely influenced by the abundance of aphids and temperature. Before pupation, the fourth instar will stop foraging for 24 hours and attach itself to a substrate with the tip of its abdomen. After emergence from the pupal casing, Coccinella septempunctata has very soft elytra that lack pigmentation. The characteristic coloration develops with time. The red and black pigments of the elytra are derived from melanins, while the lighter areas develop from carotenes. ("Coccinella septempunctata L.", 2011; Beverley, et al., 2012; Cantrell, 2011)

Reproduction

Coccinella septempunctata reproduces sexually, with each male and female copulating with multiple partners in a breeding season. Males court females with a five step display: approach, watch, examine, mount and copulatory attempt. During the approach stage, a male will come within 1 cm of a desired female and watch her without making contact. The male will then examine the female by feeling her antennae and mouth with his own (examine). If suitable and accepting, the male will mount the female by climbing onto the elytra from behind and attempt copulation.

A sexually immature female will resist courtship from a male, along with females that have recently mated or are about to lay eggs. In one day, an individual might mate 4 to 6 times. Each female will mate with many males over the course of her lifespan. The multiple matings of females greatly increases fecundity, viability of eggs, and percent of successful hatchings. Females of Coccinella septempunctata are known to eject spermatophores, but do not eat them. There are no data suggesting the reason for spermatophore ejection in this species.

Once a female has fertilized eggs she will begin to disperse them around her environment. A female might lay anywhere from 250 to 500 eggs in her lifespan. Coccinella septempunctata females are deterred by some olfactory cues of conspecific eggs in an area, and will lay eggs in areas without other eggs of the same species. Each suitable substrate will receive a maximum of 15 eggs. It is hypothesized that this trait allows females to have higher egg dispersal rates and also decreases intraspecific competition of larvae. There is a tendency in this species to produce more eggs than the carrying capacity of the environment, which places many offspring at high risk of mortality; however, occasional high abundances of aphids might make this reproductive strategy beneficial. Some males will fertilize females shortly before diapause, which causes some females to overwinter with sperm stored in their spermathecae. ("Coccinella septempunctata L.", 2011; Beverley, et al., 2012; Cantrell, 2011; Hodek and Michaud, 2008; Omkar and Srivastava, 2002)

Behavior

Coccinella septempunctata is a motile species that can fly, and is mainly active during the day. One major aspect of this species' behavior is its tendency to aggregate during the overwintering period. Coccinella septempunctata adults will form groups of around 10 to 15 individuals (although aggregates of over 200 individuals have been documented) within the densely packed foliage of low lying grasses or in between boulders. (Angalet, et al., 1979; Cantrell, 2011; Hodek and Michaud, 2008; Honek and Martinkova, 2005; Honek, et al., 2007)

Communication and Perception

The chemical cues used by Coccinella septempunctata are fairly well documented. There are several compounds that are used throughout its life and for a variety of behaviors. This species overwinters in aggregations within dense foliage, and implements chemical cues to attract other individuals. This specific pheromone for Coccinella septempunctata was isolated and identified to be 2-isopropyl-3-methoxy-pyrazine. This cue not only attracts individuals to a relatively safe overwintering aggregation, but also ensures that the group will exit diapause with a local population to mate with. Several chemical cues are also used in finding prey, particularly aphids. For instance, the alarm pheromone that aphids release from their cornicles when a predator is sensed (used as a warning between aphids) is an attractant to C. septempunctata. Cues released by plants in response to aphid herbivory are also utilized by coccinellids to locate aphid infested plants.

Intraguild predation during the larval stage is high in this family of predaceous insects as an adaptation due to the short-lived nature of aphid colonies and the limited distances that larvae can travel to locate food. Due to this high evolutionary pressure, Coccinella septempunctata is deterred by the compounds associated with hetero- and conspecific eggs, which decreases the likelihood of offspring mortality due to cannibalism and predation. (Cantrell, 2011; Peterson, et al., 2005)

Predation

Coccinella septempunctata and other coccinellids have very few natural enemies in their adult stages. The typical bright colors of coccinellids, with high contrasting orange and black spots, functions as aposematic warning coloration. The visual cue of toxicity seen in coccinellids is successful in deterring most predators, but chemical signals are also a major defense component. Coccinella septempunctata has several toxic N-oxides and alkaloids that exude from the gland between the femora and tibia. These chemicals can be released due to threats or attacks from predators and can account for up to 20% of the body weight of the beetle. These compounds are highly toxic to many common beetle predators like birds and small mammals. Spiders are also known to prey on Coccinella septempunctata larvae. Intraguild predation and cannibalism on eggs and larvae are also significant threats. The fourth larval instar is the most vulnerable instar to predation, with a significant number of individuals perishing during this stage, though the explanation for this trend has yet to be explained in a controlled study. (Abassi, et al., 2001; Angalet, et al., 1979; Cantrell, 2011; Hodek and Michaud, 2008; Honek, et al., 2007; Kindlmann, et al., 2000; Miura, 2009; Peterson, et al., 2005; Riddick, et al., 2009)

Coccinella septempunctata serves as host to a large variety of parasites and parasitoids. Parasitic wasps
of the families Eulophidae and Braconidae, and flies of the family Phoridae parasitize the larvae of C. septempunctata. The braconid wasps Perilitus coccinellae and Dinocampus coccinellae are the most well known species that are parasitoids of Coccinella septempunctata. P. coccinellae develops in sync with the larvae and/or adult of the ladybird beetle and will even remain at the diapause induced state until the host comes out of diapause. D. coccinellae eggs are typically deposited within the body cavity of a female of Coccinella septempunctata and proceed to hatch and eat the eggs of the female. The host is unaffected by the further progress of this wasp larva until it pupates within a leg of the host and emerges as an adult up to 9 days later; some adults are apparently able to revive from this emergence event and continue their life cycle. (Abassi, et al., 2001; Riddick, et al., 2009; Triltsch, 1996)

Economic Importance for Humans: Positive

Coccinella septempunctata is a common species used for biological control in agriculture settings, as its main prey is the aphid, a major agricultural pest. Aphids are small Hemipterans that eat the phloem from a diverse set of plants and can have devastating effects on crop yields. Aphids also harm plants by indirectly transferring diseases and fungi. C. septempunctata is one of the most successful aphidophagous insects and has been employed across the U.S. to control aphid populations. The ability of C. septempunctata to be so successful in a large range of habitats makes it especially beneficial to humans who need crop security from aphid infestations. ("Coccinella septempunctata L.", 2011; Honek and Martinkova, 2005; Peterson, et al., 2005; Tatchell, 1989)

Positive Impacts

controls pest population

Economic Importance for Humans: Negative

Many native coccinellid species are being driven away by Coccinella septempunctata; unrealized human benefits from these native species could therefore be lost as Coccinella septempunctata continues to dominate more and more ecosystems. Emerging dominance of this species outside of agricultural landscapes could detriment overall ecosystem health. Any retrospective restoration efforts could be costly to humans. Coccinella septempunctata is also a nuisance to the wine industry, as it is sometimes accidentally caught on crops and incorporated during the wine making process. Chemicals produced by C. septempunctata taint the taste and quality of wine. ("Coccinella septempunctata L.", 2011; Botezatu, et al., 2013; Honek and Martinkova, 2005; Peterson, et al., 2005; Tatchell, 1989)

Conservation Status

Coccinella septempunctata is considered an invasive species and is not on any conservation lists, globally, nationally, or within any state.

Contributors

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

agricultural

living in landscapes dominated by human agriculture.

aposematic

having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

delayed fertilization

a substantial delay (longer than the minimum time required for sperm to travel to the egg) takes place between copulation and fertilization, used to describe female sperm storage.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diapause

a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.

diurnal

active during the day, 2. lasting for one day.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

poisonous

an animal which has a substance capable of killing, injuring, or impairing other animals through its chemical action (for example, the skin of poison dart frogs).

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sperm-storing

mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.

suburban

living in residential areas on the outskirts of large cities or towns.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

Turnock, W., I. Wise, F. Matheson. 2003. Abundance of some native coccinellines (Coleoptera: Coccinellidae) before and after the appearance of Coccinella septempunctata. The Canadian Entomologist, 135: 391-404.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.